FRET-based ratiometric fluorescent probe for Cu2+ with a new indolizine fluorophore

•A ratiometric fluorescent probe for sensing Cu2+ based on new fluorophore indolizine has been synthesized.•The probe exhibits highly sensitivity and selectivity toward Cu2+ (detection limit: 9.1 nM).•The ratiometric fluorescent probe displays a remarkable emission shift (up to 193 nm).•The probe show low cytotoxicity and can be applied in cells.

A new fluorophore indolizine was synthesized and used as a donor to construct FRET system. The chemodosimeter shows a large Stokes shifts (193 nm), high sensitivity, and high selectivity. The probe can quickly (10 min) detect Cu2+ effectively in a wide pH range from 5 to 12 and with a detection limit as low as 9.1 × 10−9 M. Furthermore, it could be used for imaging Cu2+ in living Glioma cells which demonstrated its value of practical applications in biological systems.

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